(v13) Preboot device

This page applies to Harlequin v13.1r0 and later; and to Harlequin Core but not Harlequin MultiRIP

The Preboot device (device number 18) is a parameter-only device that provides the necessary information to make the Union device and ZIP SW options work properly. The Preboot device implementation is provided by the skin or SDK, and used by the core to mount and configure devices, possibly including the %os% device, before the RIP finishes booting.

If a Preboot device is discovered by the core during boot up, then its parameters are enumerated. The device's parameters are expected to be composite parameters, each with a key name and a dictionary value. The device named by each parameter key will be mounted, and then the dictionary will be enumerated for key-value pairs to set as parameters on that device.

If the %os% device is mounted by this sequence, then the RIP boot continues as normal. If the %os% device is not mounted by this sequence, or there is no Preboot device, then the %os% device is mounted using a filesystem device (device number 0, also known as OS_DEVICE_TYPE for the operating system's file device) with the SW folder set as the Prefix of any instance mounted as %os%. This method ensures compatibility for older RIPs and RIPs that lack a Preboot device, but provides options for mounting union, ZIP, or other complex devices before boot.

If a configuration generator device (%configps%) is desired by the OEM, then it could be added to the list of devices returned as parameters by the Preboot device.